


The World Begins to End

by cy_chase, Palpalou



Category: Marvel (Movies), The Avengers (2012)
Genre: AU, Alternate Universe - No Powers, Alternate Universe - Zombies, Character Death, M/M, Science
Language: English
Status: Completed
Published: 2012-09-09
Updated: 2012-09-09
Packaged: 2017-11-13 22:51:14
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, Major Character Death
Chapters: 1
Words: 4,400
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/508579
Author URL: https://archiveofourown.org/users/cy_chase/pseuds/cy_chase, https://archiveofourown.org/users/Palpalou/pseuds/Palpalou
Summary: <blockquote class="userstuff">
              <p>The world doesn't end on December 21, 2012. It only starts to end, and when the zombie apocalypse happens, it's nothing like anything, not movies, not television, not video games or books, could have possibly predicted.</p>
            </blockquote>





	The World Begins to End

**Author's Note:**

> For the Avengers Reverse Big Bang 2012. Inspired and enhanced by the lovely art of daffenger. I can only hope I did it justice!
> 
> Thanks to Clarissa for the rapid beta :)
> 
> Story notes:
> 
> CDC = Centers for Disease Control (and Prevention) in Atlanta, GA  
> USAMRIID = United States Army Medical Research Institute for Infectious Diseases, Fort Detrick, MD
> 
> Science 'ranks': the lab leader is referred to as the PI, principle investigator. Post-docs have received their PhD but are still in training (like a medical residency). Grad students are in the process of doing thesis work toward their PhD.
> 
> Labs in the story:
> 
> Banner Lab: Loki Laufeyson, postdoc  
> Stark Lab: James Rhodes, postdoc; Pepper Potts, postdoc; Steve Rogers, grad student  
> Coulson Lab: Bucky Barnes, Clint Barton, Natasha Romanov, junior research scientists  
> Foster Lab: Darcy Lewis, grad student  
> Other labs mentioned: Pym, McCoy, Lensherr, Richards, Hill
> 
> Link to full-size images in the endnotes.
> 
> Spoilery notes at the end (check for if you're concerned about triggers related to zombies or character death)

The world doesn't end on December 21, 2012. It only starts to end, and when the zombie apocalypse happens, it's nothing like anything, not movies, not television, not video games or books, could have possibly predicted.

_1992_

_Loki Laufeyson is 12, and so very out of place. A foster kid with no pending adoption, first day on scholarship at the most exclusive private school in Oslo, and his uniform is too short in the sleeves and too long in the legs, and his tie feels like it's going to strangle him._

_The kid sitting to his left in homeroom looks over at him, takes in his fidgeting, and Loki gives him a sidelong glance, features schooled to neutral. The kid, with perfectly combed, shoulder-length blond hair and an impeccably tailored uniform beams at the attention, whispering such that Loki is sure he has no idea what a whisper is. "I'm Thor. What's your name?"_

_"Loki," whispers Loki properly, eyes on the blackboard, back perfectly straight._

_Somehow, though, he can still sense the blond boy's beaming face, his excited wriggle. "Truly? I always wanted a brother!"_

And that's how Thor treats him, from that moment on. He invites Loki over to his mansion, and doesn't say a word when Loki shyly brings him up to his foster family's two-bedroom apartment, seemingly content to read comics by torch in the back corner of Loki's closet, which is a hiding place he's far too old for and has never told anyone about.

Thor plays football and handball and hockey like he was born with balls in his hands and skates on his feet, and Loki pretends he doesn't adore lurking in the top of the bleachers to watch his friend play. He also pretends he doesn't know every rule of all of Thor's sports, pretends rather well that he doesn't appreciate all the nuances.

Thor comes to Loki's extracurriculars too, when they involve spectators, which isn't often. But he was browsing project boards at the National Science Fair, dutifully reporting back that Loki's was definitely the best, and when Loki spotted his stupid blond head in the crowd at the city chess championships, he felt a warm curl in his belly that had nothing to do with the checkmate he was going to achieve in less than ten moves.

Loki assumes that he figures it out first, about Thor being more than a friend, and different than a brother, because he gets a grant to go study in France after they graduate, and he turns it down. He tells Thor in the backyard of the Odinson mansion, their trouser legs rolled up, feet dangling in the pool; it's almost dawn and they're alone. "I'm staying here for university," he murmurs. Thor has a contract with Valerenga to play football; he's not going anywhere.

Thor laughs, deep and booming, and his big hand curls around Loki's jaw, and he kisses him within an inch of his life, and Loki realizes he might not have been first, after all.

Loki gets his degree from the University of Oslo and Valerenga wins the Tippeligaen, and when coincidentally, Thor is sold to Rosenborg in Trondheim, Loki gets accepted to the University of Science and Technology to do his master's course.

It's a surprise to Loki when he looks up at the end of his PhD defense and Thor is (still) beaming at him from the back of the room, and they’ve been inseparable for over a decade and a half, Loki staying with Thor in Norway, and Thor following Loki to Oxford, to England. Loki has cell cycles and fungal growth rates and climate change data swirling in his head but when Thor envelopes him in a hug, it all sort of fades away, and Loki wonders when in the last sixteen years he stopped feeling like an orphan.

He has a feeling it was around 12.

That night, sweaty and sated and tangled in each other and the sheets, with the breeze sweeping over them from a wide-opened window, Loki traces absent protein structures on Thor’s skin. “I have an offer from CDC, in America.”

“They have football in America,” says Thor easily, like he hasn’t spent the last four years leading Oxford United back into League One, like getting yourself sold is so easy. Loki thinks of the academic couples he’s known, and can’t help but grin at the absurdity of a member of the Norwegian National Team being the lagging spouse.

So they go. To America, Atlanta, the newly-minted Doctor Laufeyson to a post-doctoral fellowship at CDC, Thor to the North American Soccer League.

Three years later, the world ends.

“Doctor Banner!” Tony Stark, PhD, MPH, MD, is hovering in the door to the lab, his own students and post-docs in a smirking trio behind him. Stark’s eyes are wide and wet, and he’s bouncing with excitement, and Bruce, Loki’s own boss, looks up from the microscope with an ever-suffering sigh. “Doctor Banner, sir, will you please sign my National Geographic?” He waves the magazine clutched in his fist, bouncing over to where Bruce is seated. “You’re so _dreamy_.”

“Very funny, Tony,” Bruce murmurs, giving his colleague a subdued half-smile.

Stark laughs, claps Bruce on the shoulder, and speed-walks out of the lab, followed by Pepper and Rhodey, though Rogers, the only graduate student in a lab full of post-docs, stays behind.

“Doctor Banner, congratulations on the article. I think it’s really great.” He smiles wide and sincere, and even though Loki’s pointedly unengaged from the conversation (his fungal DNA isn’t going to extract itself), he can tell that Bruce ‘s smile widens a little too.

“Thank you, Steve,” he smiles, and Rogers hurries after his labmates.

“You _did_ know what was going to happen when you agreed to interview,” Loki murmurs, adding ethanol to each of his tubes.

“It’s important,” Bruce shrugs, mild-mannered as ever, and if Loki hadn’t _seen_ him at last year’s conference on climate change, shoulders square, eyes dark and flashing, _scary_ in his vehemence, he’d think Doctor Banner didn’t really care about his subject _that_ much. “This way it gets out to the public through me, not through the media desperately trying to interpret one of our papers.”

“‘Forget the weather. Forget earthquakes, and asteroids, and bacterial infections. If there’s something you should be afraid of in the next 50, 100 years, it’s the fungus.’ You don’t think that’s overkill?” Because Loki did read the article, even if he wouldn’t have agreed to give the interview to NatGeo in the first place.

“I don’t,” Bruce answers succinctly, and Loki can only shrug, innocuous bits of fungal DNA safely drowned in neutralization buffer.

***

December 21 is the winter solstice in the northern hemisphere, and while Loki can’t recall ever believing in any sorts of gods, he likes that it’s the darkest day of the year, and maybe he likes the guarantee that the next day will be a few minutes lighter. So even though Bruce is still in his office, and the entire Stark lab is as loud and active as ever, Loki lets Thor pick him up at five. They go to the Westin in downtown Atlanta for dinner, because the skyscraper hotel has a rotating restaurant at the top. Thor likes to look out over the city, and Loki likes the way the sunset reflects off Thor’s hair, so really it’s a win/win, even though it means neither of them eats very much.

“I got you something,” Thor beams, as Loki toys with his pasta, and Loki glares, because _every year_ there is a strict agreement of _no gifts._

But Thor has really horrible puppy dog eyes, and Loki knows from the beginning he’ll relent.

He isn’t expecting a ring.

“Not here,” Thor says scornfully, narrowing his eyes, because there are things about living in the conservative areas of the United States that he despises, and has told more than one reporter about in great detail, even when they just were looking for a couple quotes about the foot-- soccer game. “At home. In Norway, when we return.”

“Next summer,” Loki half-asks cautiously, staring at the band in his palm. “Really? You want to--”

“Next summer,” Thor booms, ignoring the end of Loki’s thought and drawing the majority of attention in the previously quiet restaurant.

Loki doesn’t slip the ring onto his finger until they’re back in the car. “Yes,” he says, finally, eyes on his hand, terrified at the idea tying himself to one person, declaring them a family, because it didn’t work out so well for him the first time. He’s stubborn enough to do it anyway.

Thor just laughs, because somehow he’s always known what goes through Loki’s head, and he’s always been able to make the thoughts fade.

It delays their departure from the parking garage, but it works this time too.

***  
In all honesty, Loki would just as soon work on Christmas Day, when the lab is silent and nobody’s around to pester him for reagents and protocols, but Thor won’t let him, so he’s still in bed with an affectionately aloof cat and an aggressively cuddly dog when his phone buzzes.

 _Get here now. All hands._ is the succinct text from Stark and there’s something about the tone that makes Loki scramble. Thor gives him furrowed eyebrows when he strides into the kitchen fully dressed, but Loki can only shrug. “Emergency,” he says, plucking a searing-hot slice of French toast from the griddle and tossing it from hand to hand until it’s cool enough to eat on his way out the door.

Loki already knew it was serious, because it’s a federal holiday, and CDC is a federal entity, but his gut tightens a little bit when he sees the uniforms. USAMRIID is here, and if the Army is briefing CDC, something major has happened.

If the Army is briefing the CDC’s fungal pathogen group, it’s something to be seriously afraid of.

Loki knows the Coulson lab, of course, he’s read all the papers they actually have clearance to publish, and a bit beyond that, because apparently Rogers used to serve with-- well, probably the dark-haired captain at the front of the room who keeps smirking at Steve.

“People,” Coulson barks, after Stark has slipped into the back of the room with two giant cups of coffee, one of which he hands off to Banner. His three junior officers spring into motion, handing out thick folders to all the researchers in the room. “We have a situation.”

***

“It’s fucking terrifying,” Captain Barnes (‘seriously, though, call me Bucky’) murmurs, hours later. Colonel Coulson is in a closed-door meeting with Stark and Banner; the rest of them are grouped around a conference table covered with pictures and graphs and autopsy reports. The assorted lab liquor stashes are flowing freely, and Barnes, Barton, and Romanov have moved past data and into the eyewitness accounts.

“Flu-like symptoms,” Barton sighs, rubbing his face and unbuttoning the top of his uniform. “They just-- had a fucking _cold._ ”

“Until it wasn’t.” Romanov is working her way steadily through Pepper’s vodka, red hair beginning to fall from its severe bun.

Loki has never met these three, but he’s read their work, knows they’ve been around the world with the Army and seen some undeniably shitty situations, and if this is enough to leave them all wide-eyed with fear and exhaustion, he’s going to take it seriously. “But it’s just Brazil, yeah? You said twelve cases, ten in Sao Paolo, two in Rio.”

“Laufeyson,” Barton shakes his head, eyes serious. “Flu-like symptoms, a seeming recovery _lull_ before they-- and we can’t find the transmission mechanism? How long do you think it’s going to stay in Brazil?”  
Loki swallows his whiskey and pulls out his phone, because it’s going to be a long night, and he should Thor know, but he doesn’t get very far before Pepper grabs his wrist. “Loki! Is that...when did you...?” She looks torn between excitement that Loki seems to have gotten himself engaged, and dismay at the timing.

Loki carefully disengages his hand, thumb stroking over the ring. “Couple days ago. It’s-- we should get to work.”

But Rhodes lifts his plastic cup of scotch and slowly the others follow suit, and Loki feels uncomfortable, so he raises his chin and gives a small smile. But it’s not like they all don’t have something to fight for, even if the fight is, right now, wholly undefined.

***

They work through the night on the sequencing data Coulson brought with him, hoping to get a step ahead of the physical samples coming in the morning, until Loki’s eyes blur from endless rows of A, C, G, T, structures he can’t begin to figure out, proteins that don’t match anything in the massive genetic databases hosted by the NIH. He gets abruptly to his feet around 3am, raising his eyebrows at Barton, who gives him a grateful nod in response. Two coffees, then. 

He sees the shadow in the break room before he gets there and halts, picking up the low voices. “It was like-- it was like it was normal, Cap.” Barnes’ voice is shaking, muffled, and Loki realizes suddenly from the merged shadows that they’re pressed together. “We walked in, and this woman was-- was--”

A choked sob, and Loki’s heart beats faster. “I know,” Steve is soothing. “We’re going to figure it out, Bucky, we’re going to fix it, I _swear.”_

“Her own _kid,_ ” Barnes forces out, and Loki feels suddenly, abruptly _sick._ “She didn’t even know it was-- she just sat there, _smiled_ at us, there was so much fucking blood--”

And Loki can’t take it anymore, because he deals with DNA and proteins and genomes and not _real people_. He scuffs his feet on the tile and gives Barnes and Rogers time to separate before he heads for the coffeepot, pretending not to see Steve’s ashen face and Barnes’ red eyes, and the way Bucky’s hand is still fisted in Steve’s shirt. He just pours coffee for himself and Barton, and goes back to the lab.

They’ll fix this. They have to.

But it’s nothing they’ve seen before, not even close, and if it weren’t for the fact that Loki had redrawn the phylogenetic trees over and over and over, with every model he knows, he’d barely believe it was a fungus.

“It’s not so unusual,” Pepper sighs wearily as they mainline coffee and pick at bagels in the group meetings they have every third morning or so. The Coulson lab never really left, and Loki has grown accustomed to them in civilian clothing, fitting in around the researchers and technicians that work around the clock for six weeks now. “We’ve known for years fungi can affect behavior in far more complex ways than other pathogens.”

“We all know about the ants that let themselves get eaten by cows,” Barton sighs, head resting on his forearms.

“And the mice, too,” Barnes supplies, like they haven’t all read these papers. “The ones that like the smell of cat urine.”

“We actually tried to get a grant funded on that,” Natasha says, shaking her head. “To study the mice, see if we could counteract the behavioral effects.”

“It was denied,” Clint says, raising his head and rolling his eyes. “Something about lack of applicability...?”

Loki doesn’t jump in, just stares at the protein model on his laptop screen and tries to make it make sense. But it doesn’t, and the global pandemic continues, and even with closed borders, Loki knows it’s only a matter of time before the United States is overcome too.

The CDC locks down when the first reported case shows up in New York, and Loki could almost kiss Pepper, who knew from Steve, who got it from Barnes, that the closed gates were coming. As a result, Thor is safely ensconced in the conference room when the lockdown hits, and the whole group stands at the window, watching the big, iron gates swing closed and the guard station blockade go up and Loki is glad for Thor’s big hand at the small of his back, holding him steady.

***

Cell coverage goes first, then cable. Bruce and Tony and Phil slowly start filling every whiteboard in CDC with equations and diagrams in Sharpie, copying down data as soon as the rest of them generate it, preparing for loss of power, loss of internet, loss of everything they’ve worked _months_ to get. They run out of whiteboards and start in on walls, and Loki will sit in ‘his’ room for hours on end, feeling like he’s so close to an answer he can taste it, and hopeless because he doesn’t even know what the state of humanity is outside their gates, but he can’t help but feel responsible.

“It isn’t your fault,” Thor tells him one night, arms tight around his middle, one finger stroking the cat in Loki’s lap (because of course Thor brought pets into apocalyptic lockdown with him).

Loki just sighs, because it’s not, but it is. “We all feel that way.”

“You’re all morons,” Thor says bluntly, drawing a smile from Loki. “I’ve seen-- I _know_ how hard you’re working, all of you. Nobody could be expected to do better.”

“Humanity could be ending,” Loki answers. “And we can’t figure out why, or how to stop it.”

Thor waves his hand at the neat, black lettering on walls and windows. “ _Look_ at how much you know!”

“It’s not enough,” Loki whispers, leaning back, closing his eyes. “None of it is enough.”

***

They’re on emergency power and the intranet has been reduced to the few labs still toiling away: Stark and Banner, displaced Coulson, Foster, Hill, Pym, Richards, McCoy, Lensherr. Nobody Loki had worked with before, just full labs who used to work on entirely different systems, now willingly in lockdown and writing on walls just like the rest of them. They have full meetings now, every morning, and it’s really more for everyone’s sanity than any scientific value, because even though the Coulson lab doesn’t even call _each other_ by ranks anymore, and the designations between student, postdoc, and principle investigator have eroded entirely, they’re stuck in this complex with lessening stores of food and caffeine and no link to the outside world anymore.

And it’s one of those meetings that Loki-- realizes.

It’s something Foster’s student says as they’re all looking at a hand-drawn protein structure on an overhead projector (Steve is appalling good at hand-drawing the things), sighing and resting her cheek in one hand. “It looks like a fucking _pheromone_.”

Loki sits up, pointing at Darcy. “Say that again.”

“It looks like a fucking pheromone?”

Everybody’s looking at him, and his heart pounds as he flips through his papers to find the origin of the protein they’re all looking at. “Fuck me.” Stark makes a small noise, like he wants to comment, but other than that, silence remains. “It _is_ a pheromone. This is-- this was isolated from the victims _and_ the...” He swallows. “This is why we couldn’t-- transmission is, oh god, the viruses, this is so much more--”

He can tell they’re all lost, _he’s_ lost, and he scrambles to his feet, not even feeling Thor’s fingers on his arm, settling a new transparency on the overhead and trying to put his jumbled thoughts into something comprehensible.

Loki crosses shaking hands over his chest and steps back. “It’s been there all along. We just-- we weren’t--”

“We’ve never seen anything like this,” Coulson says grimly. “Dual infection, sure, but...coevolution like this? Two viral life cycles, promoting spread and...jesus.”

“It explains the patterns,” Banner murmurs. “The victim is almost always someone close to their attacker, sharing a home.”

“And the hyphae in the gut,” Stark adds, still for once, stoic. “That’s how they get their trigger from the virus, which--”

“Replicates in the brain,” Loki finishes, numbly.

“It’s cryptic fucking rabies,” mutters Barnes. “But with a nasty fungus mixed in.”

“Boys and girls,” Coulson says, and suddenly he’s smiling, eyes just a little crazy. Loki approves. “I want this verified yesterday. If Laufeyson’s right, then we have a way in. We can vaccinate against the little bastard.”

***

Three weeks later they have data, and hope. They’re also out of food.

“It just makes sense,” Barton says as he straps on a holster and checks the magazine of his gun. He’d taken bench space in Banner’s lab, and Loki had grown rather...accustomed to having him around. “This is your show now, you and the big guns.” He waves his hand to where Romanov, Barnes, and Rogers are waiting in the hallway, similarly equipped and grins. “The four of us, we were _trained_ for this. It’s going to be just fine.”

They return with a pickup full of supplies and nothing but bad news about the world outside, reports of empty streets and a desolated downtown, abandoned cars and very few people. Loki gets the impression they had to fight a few of those people off, but he doesn’t ask, and neither does anyone else.

“Do you think it’s like this everywhere?” Thor asks him late that night, hand stroking Loki’s bare thigh as they pass one of the bottles of vodka that came in on the supply run back and forth.

“Worse some places,” Loki murmurs, head resting on Thor’s shoulder. “Better others.”

“My family--”

Loki shifts over Thor’s lap, setting the bottle aside and threading his fingers into blond hair. “I think...I think they’re ok.” Loki doesn’t know, not really, how could he? But to put Thor at ease, he will absolutely make shit up. “Low population density, and they can close themselves off pretty effectively. They could make it.”

“Are _we_ going to?” Thor asks, starting to smile as he draws Loki closer.

“You still owe me a wedding,” Loki affirms into a kiss. “So we have to.”

***

A week later, Loki’s headed from his makeshift quarters back up to the lab when he hears what is unmistakably a gunshot. By the time he follows the noise, whatever happened is over, and it’s just Barton, bleeding out on the floor, Coulson cradling his head, service weapon at his side. “I’m sorry, sir,” Barton is wheezing, and Loki can see that Phil’s hand is slick with blood when he clasps Clint’s. “I didn’t know-- I don’t know how I-- I didn’t want to hurt you, I never wanted--”

“It’s ok,” Phil’s saying, not noticing Loki, nor the footsteps bringing the others in earshot. “It’s not your fault Clint, this isn’t your fault. Nothing to forgive, not by me, not ever.”

Natasha bumps into Loki and gasps, clinging to his arm, hand covering her mouth, and Barton’s still murmuring, but too low for Loki to hear, and he wouldn’t want to anyway. It’s obvious whatever he’s saying is for Coulson’s ears only.

And then he’s still. They’re all motionless, in shock, but Coulson gets resolutely to his feet, blood-covered and haunted and every inch the soldier. “Romanov, get Barnes and Rogers _now_ and get into isolation. Laufeyson, call a briefing. We need a protocol for leaving the compound.” They obey, because there’s nothing else to do.

Nobody else is infected.

***

Pym has a breakthrough on the vaccine three days later, and Loki stares at his hands when Coulson slips out of the room at the proclamation. They’re a family now, a dysfunctional, asocial, work-obsessed bunch of loners, united by a hopeless cause, and losing Clint like that, so close to being able to save him...it affected every one of them.

But some more than others. “I...I’m sorry,” Hank says, clearly at a loss.

“You should not be ashamed, Doctor Pym,” Thor speaks up from his usual spot in the corner, and he sounds angry. “None of you should. I have been here and seen you all run yourselves into the ground for over a year, and not one of you gave up.” He shakes his head, blond hair beyond his shoulders now. “I cannot imagine that this work could have happened any faster.”

“Phil and Clint--” Natasha speaks up, twisting her fingers together until Barnes catches one of her hands and holds it between his own. “They were always-- but they _couldn’t_. Coulson was our direct superior. But here...”

There’s a long silence, until Coulson’s voice comes from the doorway, soft but steady. “Please, Hank, continue. We’re going to beat this thing.”

In the end, they can’t stay at CDC any longer. They pour all the compound’s remaining power (and, Loki’s pretty sure, all the scientists’ remaining ingenuity) into manufacturing vaccine, as much as they can possibly carry, and Steve painstakingly draws out dozens of copies of the vaccine protocol for all of them, for when they run out and will have to try to find university facilities to make more. Coulson and Romanov pull all of security’s leftover weaponry and teach every last scientist to load their gun and clean it, if not necessarily to shoot straight.

Loki takes notes from the walls, indelible ink on waterproof paper, everything he doesn’t trust to his memory, and winter is back again when they all gather, cases of precious vaccine and sterile syringes packed tightly into backpacks, guns and food stores doled out, teams formed and maps marked.

Coulson surveys them, because he’s the undeniable leader and has been since the beginning, but all he says is, “I’m exceptionally proud of all of you. Stay together, stay safe, do the best you can. We’ll meet again.” He’s headed into the deep South with Natasha, Barnes, and Steve.

It’s enough to stir the group, and with solemn hugs and handshakes, the teams split off in all directions, to save the world.

Loki and Thor make their own team, with the dog trotting alongside and the cat close by, heading northwest into the Great Lakes region. Loki turns back after hours of walking as they crest a hill outside Atlanta. The skyline’s still there, but the city really isn’t: the people are gone, and nature has begun its reclamation project. “So,” Loki says, breath coming in visible huffs in the chilly air, glancing over at Thor’s newly-shorn hair and pink cheeks, wanting to erase the other man’s worried expression at the journey ahead of them. “Still want that summer wedding?”

And Thor laughs.

**Author's Note:**

> Major Character Death: Clint Barton  
> Trigger Warning: Implications of cannibalism, non-graphic violence  
> General warning: excessive use of science
> 
> Images can be found here: https://plus.google.com/photos/116669835554139238382/albums/5786367158583877681


End file.
